The Department of Energy (DOE) established the Idaho
National Laboratory (INL) in Idaho Falls, Idaho and three
gaseous diffusion plants (GDP) at: the K-25
Complex at Oak Ridge, Tennessee; the Paducah
Gaseous Diffusion Plant in Paducah, Kentucky; and the Portsmouth
Gaseous Diffusion Plant in Portsmouth, Ohio. At each of the
GDPs, uranium hexafluoride gas (UF6) was "enriched";
meaning the relative amount of uranium-235 isotope was increased.
This was accomplished by moving UF6 through a multi-stage series
of porous membrane "barriers." This enriched UF6 was
a necessary ingredient in nuclear weapons production and is now
used in the civilian nuclear power industry.